Biotecnología de la Reproducción, Estación Experimental Agropecuaria Balcarce, Instituto Nacional de Tecnología Agropecuaria, Argentina.
Anim Reprod Sci. 2012 Jul;133(1-2):10-5. doi: 10.1016/j.anireprosci.2012.06.001. Epub 2012 Jun 9.
This study was designed to evaluate in suckling early pregnant beef cows with and without eCG-pre-stimulation: (i) the influence of day gestation (from 40 to 101 days) and the consecutive eCG treatments on the follicular growth induced by means of ultrasound-guided transvaginal follicle ablation (FA; all follicles ≥ 5 mm) and the number and quality oocytes recovered by ovum pick-up (OPU) and (ii) the possible effects of repeated hormonal stimulation and FA/OPU on pregnancy outcome. Twelve suckling early pregnant Angus cows (40 days post fixed-time artificial insemination) were randomly assigned to each of two groups (n=6 group(-1)). Group 1 treatments included: FA (Day 0), eCG (1600 IU; Day 1) and OPU (Day 5). Group 2: as cited Group 1 with no eCG treatment. In both groups, OPU was repeated five times (Days 45, 59, 73, 87 and 101 of gestation). The numbers (mean ± SEM) of class II (5-9 mm; 4.3 ± 0.9) and class III (≥10 mm; 2.5 ± 0.4) follicles visualized per cow per OPU session in eCG-treated cows were greater (P<0.05) than for non-treated cows (0.9 ± 0.1 and 0.9 ± 0.1, respectively). In contrast, the number (mean ± SEM) of class I (<5mm) follicles per cow per OPU session was lower for cows with eCG treatment (2.8 ± 0.4) than for non-treated cows (5.7 ± 0.5). The mean number of aspirated follicles was not significantly different (P<0.05) between eCG-treated cows and non-treated cows at 45 and 59 days of pregnancy. However, the mean number of aspirated follicles was greater (P=0.03) in eCG-treated cows than non-treated cows from 73 day of pregnancy onwards. The numbers (mean ± SEM) of recovered oocytes and viable oocytes/cow/session were greater (P<0.05) for eCG-treated cows (2.2 ± 0.2 and 1.6 ± 0.4, respectively) than for non-treated cows (1.0 ± 0.2 and 0.9 ± 0.2, respectively). No donor pregnancies were lost either during or following OPU procedure. We can conclude that (1) eCG-treated pregnant suckled cows can be a source of oocytes for IVF at least to 100 days of gestation and (2) repeated FA/eCG treatment/OPU procedures did not affect the pregnancy outcome.
本研究旨在评估未经和经 eCG 预刺激的妊娠早期哺乳期肉牛（40-101 天）：（i）不同天数妊娠（40-101 天）和连续 eCG 处理对经阴道超声引导卵泡消融（FA；所有卵泡≥5mm）诱导的卵泡生长和经卵母细胞抽吸术（OPU）回收的卵母细胞数量和质量的影响，以及（ii）重复激素刺激和 FA/OPU 对妊娠结局的可能影响。12 头哺乳期 Angus 肉牛（人工授精后 40 天）随机分为两组（每组 6 头）。组 1 处理包括：FA（第 0 天）、eCG（1600IU；第 1 天）和 OPU（第 5 天）。组 2：如第 1 组，不进行 eCG 处理。两组均在妊娠第 45、59、73、87 和 101 天重复 OPU 五次。经 eCG 处理的奶牛每头每次 OPU 可观察到的 II 级（5-9mm；4.3±0.9）和 III 级（≥10mm；2.5±0.4）卵泡数（均值±SEM）大于未处理奶牛（分别为 0.9±0.1 和 0.9±0.1）。相比之下，eCG 处理奶牛每头每次 OPU 的 I 级（<5mm）卵泡数（均值±SEM）（2.8±0.4）低于未处理奶牛（5.7±0.5）。45 和 59 天妊娠时，eCG 处理奶牛和未处理奶牛的抽吸卵泡数无显著差异（P<0.05）。然而，从妊娠 73 天起，eCG 处理奶牛的抽吸卵泡数（P=0.03）大于未处理奶牛。eCG 处理奶牛的回收卵母细胞数（均值±SEM）（2.2±0.2 和 1.6±0.4）和可存活卵母细胞数/头/次（1.6±0.4）均大于未处理奶牛（分别为 1.0±0.2 和 0.9±0.2）。OPU 过程中或之后，没有供体妊娠丢失。我们可以得出结论：（1）至少在妊娠 100 天内，经 eCG 处理的妊娠哺乳期奶牛可以成为 IVF 的卵母细胞来源；（2）重复的 FA/eCG 处理/OPU 程序不影响妊娠结局。
